• Soil salinity and sodicity - global problem, exists in six continents and nearly 100 countries including Pakistan.
• Major countries - Argentina, Australia, Egypt, Iran, Pakistan, USA, Russia, India, China, Thailand and South Africa.
GLOBAL SCENARIO OF THE PROBLOM
Statistical information regarding area
Area Pakistan Punjab
(m ha)
Geographical area 80 21
Total cropped area 22 16
Surveyed area 69 21
Irrigated area 18 14
Saline and saline-sodic soil 6.68 2.68
Source: Agricultural statistics of Pakistan 2006
SOIL SALINITY/SODICITY PROBLEM IN PROVINCES OF PAKISTAN(m ha)
Punjab 2.68
Sind 2.11
Baluchistan 2.31
N.W.F.P. 0.04
Salt-Affected Area (m ha) of Punjab, Pakistan Year Area
surveyedSalt-Affected
Uncult. Cultiv. Total %
1945-46 4.84 0.42 0.49 0.91 18.80
1955-56 5.96 0.05 0.69 1.20 20.64
1965-66 6.88 0.44 0.68 1.12 16.28
1975-76 7.34 0.37 0.61 0.98 13.35
1985-86 7.57 0.30 0.58 0.88 11.62
2000-01 7.92 1.16 1.51 2.67 33.71
Source: Ahmad & Chaudhry, 2004
TUBE WELLS IN THE PUNJAB
0
200000
400000
600000
800000
1000000
1200000
1979 orbefore
1985 orbefore
1986 to1990
2002-2003 2006-2007
year
No
. of t
ub
e w
ells
Source: Punjab Development Statistics, 2006
Source: Punjab Development Statistics, 2011
No. of Tubewells in Punjab
300000
400000
500000
600000
700000
800000
900000
1000000
1999-00 2000-01 2001-02 2002-03 2003-04 2004-05 2005-06 2006-07 2007-08 2008-09
Years
No.
of T
ubew
ells
No. of Tubewells
Salinity/sodicity: 6.68 m haSalinity/sodicity: 6.68 m ha
60 % are saline-sodic in Pakistan,60 % are saline-sodic in Pakistan,
84 % are saline-sodic in Punjab84 % are saline-sodic in Punjab
(Khan, 1998)(Khan, 1998)
CROPS / PLANTS TOLERANCE WITH RESPECT TO SALINITY AND SODICITY
Field crops
S.No. English name/Common name
Botanical name 50% reduction in yield
ECe ESP
1 Millet Panicum miliaceum 19.5 20-25
2 Sorghum Sorghum bicolor 16.0 15-40
3 Sesbania Sesbenia microcarpa
15.4 50-60
4 Soybean Glycine max 7.5 16-20
5 Maize Zea mays 8.6 <15
6 Sunflower Halianthus annus 6.3 30-50
7 Cotton Gossypium hirsutum
17.1 30-50
8 Mash Vigna mungo 10.0 10-15
9 Rice Oryza sativa 7.4 60-70
S.No.
English name/ Common name
Botanical name
50% reduction in yield
ECe ESP
10 Barley Hordium vulgare
15.7 50-60
11 Sugar beet Beta vulgaris 15.0 >40
12 Lentil Lens culinaris 12.0 10-15
13 Oat Avena sativa 11.7 30-50
14 Berseem Trifolium alexandrium
10.3 20-25
15 Safflower Cathamus tinctorium
9.9 10-15
S.No.
English name/ Common name
Botanical name 50% reduction in yield
ECe ESP
16 Wheat Triticum aestivum 9.9 30-50
17 Sugarcane Saccharum officinarum
9.9 15-40
18 Canola Brassica napus 8.16 30-50
19 Alfalfa Medicago sativa 8.8 >40
20 Flax Linum ustiatissimum
5.9 25-30
21 Mustard Brassica compastis (CS-52)
Salinity/Sodicity tolerant
30-50
22 Kharchia-65 Triticum aestivum Salinity/Sodicity tolerant
30-50
Forages
S.No.
English name /Common name
Botanical name
50% reduction in yield
ECe ESP
1 Kallar grass Leptochloa fusca
22.0 >70
2 Sudan grass Sorghum sudanense
14.4 -
3 Tall fescue Festuca elatior 13.3 <15
4 Garden cress Lepedium sativum
10.0 -
5 Rhodes grass Chloris gayana 8.0 >70
6 Australian grass
Diplachne fusca
22.0 -
7 Fodder beet Beta vulgaris 19.0 <55
S.No.
Englishname /Common name
Botanical name 50% reduction in yield
ECe ESP
8 Guar Cyamopsis tetragonoloba
Salinity/Sodicity tolerant
25-30
9 Tall wheat grass
Agropyron elongatum
19.4 >40
10 Bermuda grass
Cynodon dactylon
14.7 70
11 Triticale Secole cereale X Triticum durum
13.5 -
12 Wild rye Elymus triticoides
11.0 5-15
13 Mott grass Pennisetum purporium
14 Para Grass
Brachiaria mutica 11.0 60-70
Vegetables
S.No.
English name/Common name
Botanical name
50% reduction in yield
ECe ESP
1 Asparagus Asparagus officinnalis
13.0 5-15
2 Cantaloupe
Cucumis melo 9.1 5-15
3 Pumpkin Cucurbita pepo 7.9 5-15
4 Okra Abelmoschus esculentus
Salinity tolerant -
5 Bringal Solanum melongena
Salinity tolerant -
6 Cauliflower Brassica oleracea
10.1 5-15
7 Broccoli Brassica oleraceaitalica
8.2 5-15
S.No.
English name/Common name
Botanical name
50% reduction in yield
ECe ESP
8 Spinach Spinacia oleracea
8.6 15-40
9 Tomato Lycopersicum esculentum
7.6 30-50
10 Cabbage Brassica oleracea
7.0 5-15
11 Onion Allium cepa 4.3 20-25
12 Coriander
Coriandrum sativum
Salinity tolerant
5-15
13 Garlic Allium sativum Salinity tolerant
25-30
Medicinal plantsS.No.
English name/Common name
Botanical name
50% reduction in yield
1 Hina Lasonia spp. Salinity tolerant
2 Sweet basil Ocimum basilicum
Salinity tolerant
3 Parslane Portulaca oleracea
Salinity tolerant
4 Mint Mentha veridis Salinity tolerant
5 Liquorice Glycerrhiza glabra
Salinity tolerant
6 Fenugreek Tigonella foenumgraceum
Salinity tolerant
NUTRITIONAL ASPECTS OF SALT AFFECTED SOILS
Availability of plant nutrients is affected adversely in salt affected soils and their productivity is decreased resultantly.
The main reasons for depletion in fertility of such soils are as under:-
1. Excess of certain ions like Na, CO3 and HCO3 suppress the availability of other like Ca, K, P, Zn, Mn, Fe and B. technically, it is called antagonistic effect.
2. An increase in soil pH, especially in sodic soils decreases the overall availability of phosphorus and micronutrients.
3. In salt affected soils microbiological activity is curtailed to a great extent.
4. During the reclamation process, leaching of salts is also accompanied by leaching of nutrients.
5. Nutrient uptake by plants in salt affected soils is also reduced due to decreased water uptake because of physiological unavailability of the latter.
NITROGEN
Nitrogenous fertilizer play important role in utilizing the salt affected soils for improving crop yield because
1. These soils are deficient in nitrogen.2. Low N and organic matter contents 3. Reduced microbial population4. Rate of mineralization of nitrogen is slow down. Salinity level (ECe)
above 10 dS m-1 is harmful5. Nitrogen absorption by plants increase up to moderate salinity value
(6 dS m-1) and then decreases at higher salinity values and ESP of soil.
6. The rate of conversion of one form of nitrogen to other forms is quite slow e.g. hydrolysis of urea to ammonium N was much slow down with increase in soil pH.
7. Low enzymatic activity in saline soils.8. Chloride reduces the rate of nitrification when present between 0.5- 1.0 percent.9. Ammonium volatilization loss from applied nitrogen increases with increase in pH/alkalinity of soil10. 20-25 percent over dose of nitrogen fertilizers
PHOSPHORUS
Chemistry of phosphorus is more complex in salt affected as compared to normal soils.1. The availability of P is decreased in sodic soil during reclamation.2. The availability of P in saline soil may decrease, increase or remain
unchanged depending on the nature and degree of salinity.3. Salts which change pH show more changes in the solubility of
phosphates in soils. 4. Barren sodic soils have high amounts of Olsen extractable P and
categorized as adequate in available P. 5. Amount of water soluble P increase with soil pH above 9.0.6. The availability of phosphorus increases up to moderate salinity (ECe 6
dS m-1)
7. In sodic soils, there is a tendency for increase of Ca-P form with increase in ESP and decrease in Al-P 8. In highly saline sodic soils about 10-15 percent more P is to be added and special care is to be taken for calcareous soils.9.Phosphorus absorption by plants is generally reduced with increase in salinity and ESP of soil. 10. P uptake by plants increases up to moderate salinity (ECe 6 dS m-1) and ESP (30-35) levels.
Potassium1. Increase in soil salinity depresses the K uptake by plant while Na
uptake increases.2. In sodic soil Na increases and those of Ca, Mg and K decreases.
MICRONUTRIENTSHigh pH, high CaCO3, high ESP, low organic matter content and high amount of soluble salts are the major factors responsible for micronutrients deficiencies in salt affected soils. Among the micronutrients, Zn deficiency is wide spread in sodic soils. Other micronutrients like Fe, Mn and Cu are also precipitated as their hydroxides or carbonates in highly alkaline range and may show their deficiency. In many areas particularly under poorly drained condition in medium and fine textured soil B has been reported to be present in toxic amounts.
Low nutrient use efficiency
Nutrient Efficiency (%)
Cause of low efficiency
Nitrogen 30-50 Immobilization, volatilization, denitrification, Leaching
Phosphorus 15-20 Fixation in soils Al – P, Fe – P, Ca – P
Potassium 70-80 Fixation in clay - lattices
Sulphur 8-10 Immobilization, Leaching with water
Micro nutrients (Zn, Fe, Cu, Mn, B)
1-2 Fixation in soils
Field experiments Results
RESPONSE OF RICE LINE PB-95 TO DIFFERENT NPK LEVELS
Original soil analysespHs 8.60
ECe (dS m-1) 4.72
SAR (mmol L-1)1/2 26.28O.M. (%) 0.42Available P (mg kg-1) 5.18Extractable K (mg kg-1) 86.0
Effect of different NPK rates on rice yield (t ha-1)
NPK (kg ha-1) Paddy yield Straw yield
T1 0-0-0 1.02 F 1.16 F
T2 0-75-75 2.41 DE 2.74 DE
T3 60-75-75 2.54 D 2.88 D
T4 120-75-75 3.52 AB 4.00 AB
T5 180-75-75 3.41 B 3.88 B
T6 120-0-75 2.35 E 2.67 E
T7 120-50-75 3.12 C 3.55 C
T8 120-100-75 3.63 A 4.13 A
T9 120-75-0 3.41 B 3.88 B
T10 120-75-50 3.55 AB 4.04 AB
T11 120-75-100 3.52 AB 4.00 AB
LSD 0.1714 0.2041
Nutrients Use Efficiency (%)Treatments NPK (kg ha-1)
N-Use Efficiency P-Use Efficiency K-Use Efficiency
T1 0-0-0 0.00 F 0.00 D 0.00 H
T2 0-75-75 0.00 F 7.88 BC 26.99 G
T3 60-75-75 38.99 A 9.75 B 33.65 F
T4 120-75-75 38.20 A 15.88 A 57.38 C
T5 180-75-75 27.27 D 15.72 A 54.89 C
T6 120-0-75 17.77 E 0.00 D 32.30 F
T7 120-50-75 28.93 D 5.72 C 49.82 D
T8 120-100-75 38.24 A 15.08 A 62.47 B
T9 120-75-0 32.88 C 14.93 A 0.00 H
T10 120-75-50 35.71 BC 16.41 A 70.66 A
T11 120-75-100 35.81 ABC 17.01 A 43.50 E
LSD 3.2008 2.1755 3.8113
NPK concentration in PaddyTreatments NPK (kg ha-1)
N-Concentration (%)
P- Concentration (%)
K- Concentration (%)
T1 0-0-0 1.04 F 0.13 D 0.11 F
T2 0-75-75 1.07 EF 0.26 BC 0.21 E
T3 60-75-75 1.13 DE 0.27 BC 0.27 CD
T4 120-75-75 1.28 AB 0.28 B 0.29 BC
T5 180-75-75 1.35 A 0.28 B 0.30 BC
T6 120-0-75 1.14 DE 0.15 D 0.25 D
T7 120-50-75 1.18 CD 0.26 BC 0.29 BC
T8 120-100-75 1.25 BC 0.34 A 0.32 AB
T9 120-75-0 1.19 CD 0.27 BC 0.12 F
T10 120-75-50 1.21BC 0.29 B 0.21 E
T11 120-75-100 1.22 BC 0.30 A 0.35 A
LSD 0.0720 0.0546 0.0348
NPK concentration in rice strawTreatments NPK (kg ha-1)
N-Concentration (%)
P- Concentration (%)
K- Concentration (%)
T1 0-0-0 0.31 E 0.09 E 0.79 E
T2 0-75-75 0.32 E 0.11 DE 1.05 D
T3 60-75-75 0.44 D 0.14 BC 1.14 C
T4 120-75-75 0.56 B 0.16 AB 1.25 AB
T5 180-75-75 0.65 A 0.17 A 1.24 B
T6 120-0-75 0.46 CD 0.10 DE 1.22 B
T7 120-50-75 0.50 BCD 0.12 CD 1.26 AB
T8 120-100-75 0.54 B 0.18 A 1.29 A
T9 120-75-0 0.50 BC 0.16 AB 0.74 E
T10 120-75-50 0.52 BC 0.16 AB 1.09 CD
T11 120-75-100 0.53 B 0.17 A 1.21 B
LSD 0.003 0.0294 0.0523
RESPONSE OF WHEAT TO POTASSIUM
APPLICATION IN SALT AFFECTED SOILS.
Treatments:T1: 140-110-0 kg NPK ha-1
T2: 140-110-30 kg NPK ha-1
T3: 140-110-60 kg NPK ha-1
T4: 140-110-90 kg NPK ha-1
T5: 140-110-120 kg NPK ha-1
Pre-sowing Soil Analysis:
ECe: 5.28 d Sm-1
pHs: 8.57SAR: 29.80OM: 0.36%Avail. P: 5.32 mg kg-1
Ex. K: 114 mg kg-1
Treatments
NPK kg ha-1
Grain Yield
(t ha-1)
Straw yield
(t ha-1)
K-use Efficiency
140-110-0 2.54 b 3.06 d 0.0 c
140-110-30 2.88 c 3.55 c 36.17 a
140-110-60 3.19 b 3.98 b 34.57 a
140-110-90 3.31 a 4.29 a 29.30 b
140-110-120 3.28 a 4.24 a 20.87 b
LSD 0.08 0.093 7.43
RESPONSE OF RICE TO POTASSIUMAPPLICATION IN SALT AFFECTED
SOILS.
Treatments:T1: 110-90-0 kg NPK ha-1
T2: 110-90-25 kg NPK ha-1
T3: 110-90-50 kg NPK ha-1
T4: 110-90-75 kg NPK ha-1
T5: 110-90-100 kg NPK ha-1
Pre-sowing Soil Analysis:
ECe: 6.10 d Sm-1
pHs: 8.75SAR: 37.56OM: 0.28%Avail. P: 5.90 mg kg-1
Ex. K: 110 mg kg-1
Treatments
(NPK kg ha-1)
Paddy Yield
(t ha-1)
Straw yield
(t ha-1)
K-use Efficiency
110-90-0 2.46 c 2.95 d 0.0 c
110-90-25 2.61bc 3.13 c 19.61 b
110-90-50 2.86 b 3.43 b 24.97 a
110-90-75 3.17 a 3.80 a 25.36 a
110-90-100 3.22 a 3.86 a 20.87 b
LSD 0.255 0.1593 4.510
RESPONSE OF WHEAT TO BORON APPLICATION IN SALT AFFECTED SOIL
PRE-SOWING SOIL ANALYSIS
ECe (dS m-1) 4.74-4.90
pHs 8.60-8.72
SAR(m mol L-1)1/2 24.98-28.66
O.M.(%) 0.65
Available P ( mg kg-1) 8.30
Extractable K (mg kg-1) 115.0
Available B ( mg kg-1) 0.306
Effect of different rates of boron on grain and straw yield of wheat
Treatments Grain yield ( t. ha-1)
Straw yield (t. ha-1)
T1 140-110-60 kg ha-1 3.21 E 3.32 E
T2 140-110-60 kg ha-1 +B @ 0.25 kg ha-1 3.36 D 3.41 DE
T3 140-110-60 kg ha-1 +B @ 0.50 kg ha-1 3.44 CD 3.52 CD
T4 140-110-60 kg ha-1 +B @ 1.00 kg ha-1 3.74 A 3.88 A
T5 140-110-60 kg ha-1 +B @ 1.50 kg ha-1 3.62 AB 3.69 B
T6 140-110-60 kg ha-1 +B @ 2.00 kg ha-1 3.57 BC 3.63 BC
LSD 0.1409 0.1522
Treatments Boron conc. in grain (mgkg-1)
Boron conc. in straw (mgkg-1)
Boron Use Efficiency(%)
T1 140-110-60 kg ha-1 1.24 C 1.54 C 0.00
T2 140-110-60 kg ha-1+B @ 0.25 kg ha-1 1.24 C 1.56 BC 1.39 AB
T3 140-110-60 kg ha-1+B @ 0.50 kg ha-1 1.28 BC 1.59 ABC 1.59 AB
T4 140-110-60 kg ha-1+B @ 1.00 kg ha-1 1.30 ABC 1.62 ABC 1.82 A
T5 140-110-60 kg ha-1+B @ 1.50 kg ha-1 1.34 AB 1.67 AB 1.13 AB
T6 140-110-60 kg ha-1+B @ 2.00 kg ha-1 1.36 A 1.70 A 0.86 B
LSD 0.0630 0.1165 0.8307
Post Harvest soil analysis
Treatments pHs ECe
(dS m-1)
SAR(m mol L-1)1/2
Available B(mg kg-1)
T1 140-110-60 kg ha-1
8.65 4.83 25.77 0.288
T2 140-110-60+B @ 0.25 kg ha-1
8.64 4.76 23.10 0.314
T3 140-110-60+B @ 0.50 kg ha-1
8.62 4.74 22.65 0.351
T4 140-110-60+B @ 1.00 kg ha-1
8.60 4.72 22.54 0.483
T5 140-110-60+B @ 1.50 kg ha-1
8.60 4.71 22.57 0.634
T6 140-110-60+B @ 2.0 kg ha-1
8.61 4.72 22.69 0.766
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